Electric vehicles and hybrid vehicles are known, which have a battery to operate an electric motor, which constitutes the drive motor of the vehicle. The battery has an optimal operating temperature of, for example, about 30° C., at which a high efficiency of the battery exists. It is therefore desirable to keep the current actual temperature of the battery within the range of the optimal desired temperature of the battery. Since during discharging the battery is heated by the removed power and additional thermal influences act on the battery from outside, active and also passive cooling systems are provided in the prior art. The active cooling systems contain a liquid cooling, whereas the passive cooling systems consist of insulating layers.
Thus, DE 10 2012 214 957 A1 teaches panels, i.e., insulating plates which are filled with nanoporous polymer particles. The interior of such panels is additionally under a static vacuum. The taught panels form a passive insulating system. Such insulating plates are available, for example, under the tradename va-Q-vip, wherein the porous filling can contain silica. In DE 10 2012 214 957 A1 it is proposed to arrange the panels in the vehicle directly on the body, for example, on doors, roof, floor area, or rear wall. As a result, any heating of the vehicle interior by external temperatures is reduced, which should have a positive effect on the temperature of the battery. However, it is very disadvantageous that the waste heat of the battery itself is accumulated by the panels in the vehicle interior and thus, in particular on longer journeys, the efficiency of the battery is reduced. Panels having a similar structure and similar disadvantages are disclosed in DE 10 2014 003 413 A1.
An active cooling system for a battery is disclosed in EP 2 744 033 A1. There, a plurality of rows of rod cells are arranged in separate heat exchange pockets. The heat exchange pockets have a cooling liquid flowing through them. Overall the arrangement is coated from outside by an electrically insulating film. A particular disadvantage with this proposal is that only the heat generated by the battery is removed and heat penetrating into the battery from outside is not retained. In addition, the arrangement of separate cooling pockets is cumbersome and expensive.
DE 10 2014 111 645 A1 discloses a battery housing for receiving a battery. In this case, the housing has a double wall, which is filled with a glass fiber material. A vacuum is generated in the double wall thus filled. Furthermore, an active element is arranged in the double wall, which can be heated to produce a hydrogen atmosphere in the double wall and thus reduce the vacuum. In this case, the active element can degrade and the quality of the vacuum can vary. In addition, the interior of the housing is filled with a porous material and cannot be efficiently cooled by a cooling liquid.
CN 102751460 A discloses a high-temperature-resistant composite insulating film. The high-temperature-resistant composite insulating film is formed by a combination of a polyphenylene sulfide film and a microporous polyolefin film. The film is used for the application in lithium ion batteries. However, the film is a passive insulating element, whose insulating properties cannot be varied after manufacture.
WO 2017/029457 A1 discloses a plurality of adjacent modules, which are interconnected by circulating means and which each contain at least one volume, in which a coolant or heat transfer liquid is present. The coolant and the heat transfer liquid can circulate through the volumes to regulate the heat balance of the modules. A layer is arranged on the periphery of at least some of the modules, wherein the layer is thermally insulating. The layer forms a passive insulating element. This proposal is a cumbersome solution which is not adapted for heat input from outside.